Dynamic multiple display configuration

ABSTRACT

A system and method for modifying the configuration of one or more graphics adapters and one or more displays without rebooting the system allows a user to quickly transition between different graphics adapter/display configurations. A single display driver interfaces between the operating system and the one or more graphics devices. The display driver reconfigures the one or more graphics devices to change the adapter/display configuration without shutting down or rebooting the system. Unlike a conventional system reboot performed by the operating system, the display driver checks that there are no memory leaks or error conditions during the reconfiguration.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the present invention generally relate to configuringgraphics display devices, and more particularly to configuring thedisplay devices when multiple graphics adapters are installed in asystem.

2. Description of the Related Art

Conventional graphics processing systems including one or more graphicsadapters typically need to be rebooted to reconfigure the graphicsadapters for a different adapter/display configuration. For example, thehost computer is rebooted to change from a first adapter/displayconfiguration with a first graphics adapter providing output for a firstdisplay and a second graphics adapter providing output for a seconddisplay to a second adapter/display configuration with the firstgraphics adapter and the second graphics adapter configured to provideoutput for the first display and either the first graphics adapter orthe second graphics adapter configured to provide output for the seconddisplay. Using two graphics adapters to provide output for a singledisplay is desirable to produce complex images for the single displaywith improved performance compared with using a single graphics adapterto produce the complex images.

A single display driver may be used to interface between the operatingsystem (OS) running on the host computer and the first graphics deviceand the second device. Alternatively, a separate display driver may beused to interface between the operating system (OS) running on the hostcomputer and each graphics device. When a user requests to change theadapter/display configuration, the OS initiates a shutdown in order toreconfigure the graphics devices and displays. After the graphicsdevices and displays are reconfigured, the OS restarts the system. Whenthe system is rebooted, the OS shuts down all of the applications anddisplay driver(s) and restarts the applications and the displaydriver(s). The reboot requires many clock cycles to complete and istypically avoided by users.

Accordingly, it is desirable to enable a user to change theadapter/display configuration without rebooting the system.

SUMMARY OF THE INVENTION

The current invention involves new systems and methods for dynamicallychanging the adapter/display configuration. The configuration of one ormore graphics adapters and one or more displays is performed withoutrebooting the system, allowing a user to quickly transition betweendifferent graphics adapter/display configurations. A single displaydriver may interface between the operating system and the one or moregraphics adapters. The display driver reconfigures the one or moregraphics adapters to change the adapter/display configuration withoutshutting down the system. Unlike a conventional system shutdownperformed by the operating system, the display driver checks that thereare no memory leaks or error conditions during the reconfiguration.

Various embodiments of the invention include a first display device, asecond display device, a first graphics adapter configured to provideimage data to the first display device, a second graphics adapter, and adisplay driver. The second graphics adapter is configurable to provideimage data to the first display device though the first graphics adapteror to provide image data to the second display device. The displaydriver is configured to change a configuration of the first displaydevice, the second display device, a first graphics adapter, and asecond graphics adapter from a first configuration to a secondconfiguration without shutting down the multiple graphics adapterprocessing system.

Various embodiments of a method of the invention for changing aconfiguration of a multiple graphics adapter processing system includedetermining whether a configuration specification enables or disables ascalable link interface between a first graphics adapter and a secondgraphics adapter in the multiple graphics adapter processing system andchanging from a first configuration of the first graphics adapter andthe second graphics adapter to a second configuration of the firstgraphics adapter and the second graphics adapter without shutting downthe multiple graphics adapter processing system, wherein the secondconfiguration is defined by the configuration specification.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentinvention can be understood in detail, a more particular description ofthe invention, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

FIG. 1A is a block diagram of an exemplary embodiment of a multiplegraphics adapter processing system in accordance with one or moreaspects of the present invention.

FIGS. 1B and 1C are block diagrams of other configurations of themultiple graphics adapter processing system of FIG. 1A in accordancewith one or more aspects of the present invention.

FIG. 2 is a conceptual diagram showing the communication between thecontrol panel, display driver, and graphics subsystem in accordance withone or more aspects of the present invention.

FIG. 3A is an exemplary embodiment of a method for dynamically changingthe adapter/display configuration in accordance with one or more aspectsof the present invention.

FIG. 3B is an exemplary embodiment of a method for performing step 312shown in FIG. 3A in accordance with one or more aspects of the presentinvention.

FIG. 3C is an exemplary embodiment of a method for performing step 314shown in FIG. 3A in accordance with one or more aspects of the presentinvention.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forth toprovide a more thorough understanding of the present invention. However,it will be apparent to one of skill in the art that the presentinvention may be practiced without one or more of these specificdetails. In other instances, well-known features have not been describedin order to avoid obscuring the present invention.

A system and method for modifying the configuration of one or moregraphics adapters and one or more displays without rebooting the systemallows a user to quickly transition between different graphicsadapter/display configurations. A single display driver interfacesbetween the operating system and the one or more graphics adapters.Therefore, unlike a conventional system where there may be a one to onecorrespondence between display drivers and graphics adapters, anapplication program does not need to communicate with multiple displaydrivers to distribute processing to the multiple graphics adapters.Furthermore, a unified frame buffer may be presented to the applicationprogram when the frame buffer is distributed between the multiplegraphics adapters. The display driver reconfigures the one or moregraphics adapters to change the adapter/display configuration withoutshutting down or rebooting the system. Unlike a conventional systemreboot performed by the operating system, the display driver checks thatthere are no memory leaks or error conditions during thereconfiguration. As known to those skilled in the art, a memory leak isa condition in which memory that has been allocated, but is no longerneeded, is not properly freed. As new memory is allocated, the unfreedmemory is the “leak” and eventually this condition may cause “out ofmemory” errors and/or system crashes.

FIG. 1A is an exemplary embodiment of a graphics processing system 100including multiple graphics devices, in accordance with one or moreaspects of the present invention. System 100 may be a desktop computer,server, laptop computer, palm-sized computer, tablet computer, gameconsole, cellular telephone, hand-held device, computer based simulator,or the like. System 100 includes a host processor 120, a main memory110, and a chipset 130 that is directly coupled to a graphics subsystem180. Graphics subsystem 180 includes a switch 160, and multiple graphicsdevices, graphics adapter 164 and graphics adapter 165.

A single display driver, display driver 105, stored within main memory110, configures the devices within graphics subsystem 180 andcommunicates between applications executed by host processor 120 andgraphics adapters 165 and 164. In a conventional graphics processingsystem running the Windows® OS two display drivers are used, one foreach graphics adapter installed in the system.

In some embodiments of system 100, chipset 130 may include a systemmemory switch and an input/output (I/O) switch that may include severalinterfaces such as, Advanced Technology Attachment (ATA) bus, UniversalSerial Bus (USB), Peripheral component interface (PCI), or the like.Switch 160 provides an interface between chipset 130 and each ofgraphics adapter 165 and graphics adapter 164 when a first port and asecond port of switch 160 are coupled to a connection 151 and aconnection 141, respectively. In some embodiments of switch 160, switch160 provides an indirect interface between graphics adapter 165 andgraphics adapter 164 through the combination of connections 151 and 141.Connection 167 provides a direct connection between graphics adapter 165and graphics adapter 164. In some embodiments of the present invention,connection 167 is omitted. Switch 160 may also include interfaces toother devices.

In some embodiments of the present invention, the functionality providedby switch 160 is integrated into chipset 130 and chipset 130 caninterface directly with multiple graphics adapters. In some embodimentsthe present invention, transfers over connections 141 and 151 areperformed using an industry standard protocol such as PCI-Express,™ and,in such cases, switch 160, graphics adapter 165 and graphics adapter164, each include an interface unit corresponding to the industrystandard protocol.

As shown in FIG. 1A, a primary graphics processor 140 within graphicsadapter 164 is configured to output image data to a display 170. Display170 may include one or more display devices, such as a cathode ray tube(CRT), flat panel display, or the like. Primary graphics processor 140within graphics adapter 164 is also coupled to a primary frame buffer145, which may be used to store graphics data, image data, and programinstructions. A graphics processor 150 within graphics adapter 165 iscoupled to a frame buffer 155, which may also be used to store graphicsdata, image data, and program instructions. In some embodiments of thepresent invention, graphics adapter 164 includes two or more graphicsprocessors. Graphics adapter 164 and graphics adapter 165 may each becapable of providing image data to two or more displays. As shown inFIG. 1A, graphics processor 150 is configured to output image data todisplay 170 via primary graphics processor 140.

An example of a multi-adapter configuration is a scalable link interface(SLI) configuration that permits multiple graphics devices to produceand combine image data for a single display device. The SLIconfiguration functionality is provided via switch 160 or via connection167. Additional graphics adapters may be included within graphicssubsystem 180 and coupled to each other in a chain that is coupled tographics processor 150, thereby providing the scalable feature of theSLI configuration.

In some embodiments of the present invention, the multi-adapterconfiguration is fixed when system 100 is manufactured. For example, themulti-adapter configuration information may be fixed by providinghardwired inputs to each graphics processor. In other embodiments of thepresent invention, the multi-adapter configuration information isdynamic and is updated when a second or additional graphics adapter isinstalled in system 100 or may be changed by a user via a control panel.The multi-adapter configuration information may include an indicationthat one of the multiple graphics devices, such as graphics adapter 164is a primary, e.g., master, graphics device that generates an output todisplay 170.

Display driver 105 may configure graphics processor 150 and primarygraphics processor 140 such that the graphics processing workloadperformed by system 100 is divided between graphics processor 150 andprimary graphics processor 140 to produce the image data. For example,graphics processor 150 may process a larger portion of an image thanprimary graphics processor 140. In some embodiments of the presentinvention, graphics processor 150 may process the entire image andprimary graphics processor 140 may receive the image data from graphicsprocessor 150 via the SLI. In other embodiments of the presentinvention, host processor 120 controls the transfer of the image datafrom graphics processor 150 to primary graphics processor 140.

Although system 100 as shown is a graphics processing system, alternateembodiments of system 100 may process other types of data, such as audiodata, multi-media data, or the like. In those alternate embodiments,graphics processor 150 and primary graphics processor 140 would bereplaced with other appropriate data processing devices. Likewise,display driver 105 would be replaced with a device driver correspondingto the data processing device.

FIG. 1B is block diagram of another configuration of the multiplegraphics adapter processing system of FIG. 1A, in accordance with one ormore aspects of the present invention. As shown in FIG. 1B, primarygraphics processor 140 is configured to provide image data to display170 and graphics processor 150 is configured to provide image data to asecond display device, display 172 through a connection 168. Althoughconnection 167 (see FIG. 1A) may be retained, an SLI connection is notillustrated in the configuration shown in FIG. 1B. Display driver 105may reconfigure graphics adapter 150 to provide image data directly todisplay 172 instead of to display 170 via primary graphics processor140.

The adapter/display configuration shown in FIG. 1A may be used toproduce complex or high quality images for viewing on display 170. Theadapter/display configuration shown in FIG. 1B may be used to producelower quality images for viewing on display 170 and display 172. A usermay prefer the configuration shown in FIG. 1A to play a game and changeto the configuration shown in FIG. 1B to surf the internet or performtext editing tasks. The change in configuration may be initiated whendisplay 172 is connected to graphics adapter 165 via connection 168 orby a user specifying the configuration change using a control panel. Inanother configuration of system 100 graphics adapter 165 may be omitted,and display driver 105 may initiate a change to the configuration shownin FIG. 1A when graphics adapter 165 is connected to switch 160 andprimary graphics processor 140.

FIG. 1C is block diagram of yet another configuration of the multiplegraphics adapter processing system of FIG. 1A, in accordance with one ormore aspects of the present invention. As shown in FIG. 1C, primarygraphics processor 140 is configured to provide image data to display170 and to display 172 through a connection 169. Graphics processor 150is configured to provide image data to a display 170 through an SLIconnection provided by connection 167. A change from the adapter/displayconfiguration shown in FIG. 1C to the adapter/display configurationshown in FIG. 1B may be initiated when display 172 is connected tographics adapter 164 via connection 169 or by a user specifying theconfiguration change using a control panel. Alternatively, a change froma adapter/display configuration with graphics adapter 164 providingimage data to displays 170 and 172 to the adapter/display configurationshown in FIG. 1C may be initiated when connection 167 is added,providing a SLI connection between graphics adapter 165 and graphicsadapter 164. Similarly, a change to the adapter/display configurationshown in FIG. 1C may be initiated when graphics adapter 165 is connectedto switch 160 and primary graphics processor 140.

FIG. 2 is an exemplary embodiment of conceptual diagram showing thecommunication between a control panel 205, display driver 210, andgraphics subsystem 180, in accordance with one or more aspects of thepresent invention. Display driver may receive a configurationspecification from control panel 205 or from graphics subsystem 180. Theconfiguration specification defines which graphics adapter(s) providesimage data for each display in the multiple graphics adapter system,including whether or not one or more SLI connections are enabled. A usermay view the current adapter/display configuration using control panel205 and specify changes to produce a different adapter/displayconfiguration. Alternatively, changes to the adapter/displayconfiguration may be initiated by adding or removing a display device,graphics adapter, or SLI connection. The configuration specification ofthe resulting adapter/display configuration is defined by the physicalmodifications to the multiple graphics adapter system.

Display driver 210 reconfigures system 100 according to theconfiguration specification by completing a teardown sequence and arebuilding sequence, as described in conjunction with FIGS. 3A, 3B, and3C. Display driver 210 includes a miniport 215 and a resource manager220. Resource manager 220 includes a GPU manager 225 and performs theteardown and rebuilding sequences. Miniport 215 is known to thoseskilled in the art as a kernel-mode driver specific to graphicssubsystem 180 that is linked to the operating system (OS). GPU manager225 is a portion of display driver 210 that is dedicated to, but notlimited to, managing creation/initialization/instantiation, topology,querying, linking/unlinking, state management, anddestruction/detachment related to graphics subsystem 180. GPU manager225 provides a central set of functionality for resources and provides acohesive interface for communications with graphics subsystem 180.

FIG. 3A is an exemplary embodiment of a method for dynamically changingthe adapter/display configuration, in accordance with one or moreaspects of the present invention. In step 300 control panel 205 receivesan adapter/display configuration specification. As previously described,control panel 205 is configured to receive user input defining a desiredadapter/display configuration and control panel 205 may generate theconfiguration specification in response to user input. Alternatively,the configuration specification is generated by a graphics adapter as aresult of a change in the physical connections within the multiplegraphics adapter system, e.g., installation of a graphics adapter,removal of a graphics adapter, installation of a display device, removalof a display device, addition of an SLI connection, removal of an SLIconnection, or the like.

In step 302 control panel 205 determines if there are any dependencieson the resources, e.g., graphics adapters and display devices, that willbe reconfigured to implement the adapter/display configurationspecification. If, in step 302 control panel 205 determines that thereare no dependencies, then it proceeds directly to step 306. Otherwise,in step 304 control panel 205 shuts down any applications that aredependent on the resources. In step 306 control panel 205 sends amessage to display driver 210 to initiate the adapter/displayreconfiguration.

In step 308 display driver 210 calls resource manager 220 to implementthe changes defined by the adapter/display configuration specification.In step 310 resource manager 220 determines if the configurationspecification enables or disables an SLI connection, and, if an SLIconnection is enabled, in step 312 resource manager 220 performs thereconfiguration with SLI enabled. If, in step 310 resource manager 220determines that the configuration specification does disables an SLIconnection, then in step 314 resource manager 220 performs thereconfiguration with SLI disabled. Steps 312 and 314 are described inconjunction with FIGS. 3B and 3C, respectively.

In step 316 resource manager 220 returns control back to display driver210. In step 318 display driver 210 restarts any applications that wereshutdown in step 304 and returns control back to the desktop. A user maythen specify changes to produce a different adapter/displayconfiguration or initiate changes by adding or removing a displaydevice, graphics adapter, or SLI connection. Note that thereconfiguration is completed without shutting down system 100 and thatthe reconfiguration is not necessarily initiated by the OS. Therefore, auser may transition to and from configurations enabling or disabling SLIwithout suffering a reboot of system 100.

FIG. 3B is an exemplary embodiment of a method for performing step 312shown in FIG. 3A, in accordance with one or more aspects of the presentinvention. In step 320 resource manager 220 checks the resource freestate, confirming that the resources are freed, i.e., there are nodependencies. In steps 322, 324, and 326 resource manager 220 updatesthe topology of graphics adapters in the multiple graphics adaptersystem. Specifically, in step 322 resource manager 220 checks the DMA(direct memory access) information confirming that DMA resources arefreed. In step 324 resource manager 220 checks the HEAP information todetermine if there is a memory leak. In some embodiments of the presentinvention, driver 113 includes debugging capabilities and resourcemanager 220 causes an exception and driver 113 presents an alert messageindicating that a memory leak occurred. In step 326 resource manager 220checks the CLIENT information confirming that CLIENT resources arefreed.

In steps 328, 330, and 332 resource manager 220 changes theadapter/display configuration of system 100. Specifically, in step 328resource manager 220 enables the SLI attributes in graphics adapter 164and 165 according to the configuration specification. In step 330resource manager 220 disables interrupts to ensure that no interruptprocessing happens during the actual transition to/from SLI. In step 332resource manager 220 remaps the ISR (Interrupt Service Routine).

In steps 334, 336, and 338 resource manager 220 reloads the stateinformation for graphics adapter 164 and 165. Specifically, in step 334resource manager 220 updates the topology of graphics adapters 164 and165 and the display devices, e.g., displays 170 and 172. When SLI isenabled, in step 334 resource manager 220 initializes graphics processor150 and primary graphics processor 140 and reloads the stateinformation. Specifically, in step 334 resource manager 220 attaches andcreates a BC device to enable an SLI connection. In step 336 resourcemanager 220 enables the robust channels (RC) watchdog. The RC watchdogis a thread that checks to see if graphics processors 150 or primarygraphics processor 140 is in a critical error state. When graphicsprocessor 150 or primary graphics processor 140 RC watchdog may invokeRC to try and recover from the error. In step 338 resource manager 220sets up a default vidlink routing. Vidlink is the physical link betweendevices for compositing output data output from multiple graphicsprocessors, such as graphics processor 150 and primary graphicsprocessor 140, for final display on display 170.

FIG. 3C is an exemplary embodiment of a method for performing step 314shown in FIG. 3A, in accordance with one or more aspects of the presentinvention. In step 340 resource manager 220 checks the resource freestate. In steps 342, 344, and 346 resource manager 220 updates thetopology of graphics adapters in the multiple graphics adapter system,as described in conjunction with steps 322, 324, and 326 of FIG. 3B,respectively. In steps 348, 350, and 352 resource manager 220 changesthe adapter/display configuration of system 100. Specifically, in step348 resource manager 220 disables the SLI connections in graphicsadapter 164 and 165 according to the configuration specification.

In step 350 resource manager 220 reloads the state information forgraphics adapter 164 and 165, and detaches and destroys a BC device todisable an SLI connection. In step 352 resource manager 220 disablesinterrupts. In step 354 resource manager 220 remaps the ISR. In step 356resource manager 220 disables the RC watchdog. In step 358 resourcemanager 220 removes a default vidlink routing. Persons skilled in theart will appreciate that any system configured to perform the methodsteps of FIG. 3A, 3B, or 3C, or their equivalents, is within the scopeof the present invention.

A system and method for modifying the configuration of one or moregraphics adapters without rebooting the system allows a user to quicklytransition between different graphics adapter/display configurations. Asingle display driver interfaces between the operating system and theone or more graphics adapters. The display driver reconfigures the oneor more graphics adapters to change the adapter/display configurationwithout shutting down or rebooting the system. Unlike a conventionalsystem reboot performed by the operating system, the display driverchecks that there are no memory leaks or error conditions during thereconfiguration. The display driver then unloads state information fromthe one or more graphics adapters and reloads state informationaccording to the modified configuration.

While the foregoing is directed to embodiments of the present invention,other and further embodiments of the invention may be devised withoutdeparting from the basic scope thereof, and the scope thereof isdetermined by the claims that follow. Specifically, persons skilled inthe art will recognize that the methods and systems described may beused for processing data other than graphics data where the data is usedby processors in a multi-processing data processing system. Theforegoing description and drawings are, accordingly, to be regarded inan illustrative rather than a restrictive sense. The listing of steps inmethod claims do not imply performing the steps in any particular order,unless explicitly stated in the claim.

All trademarks are the respective property of their owners.

1. A multiple graphics adapter processing system, comprising: a firstdisplay device; a second display device; a first graphics adapterconfigured to provide image data to the first display device; a secondgraphics adapter configurable to provide image data to the first displaydevice though the first graphics adapter or to provide image data to thesecond display device; and a display driver configured to interface toan operating system of the multiple graphics adapter processing systemand to change a configuration of the first display device, the seconddisplay device, the first graphics adapter, and the second graphicsadapter from a first configuration to a second configuration withoutshutting down the multiple graphics adapter processing system.
 2. Thesystem of claim 1, wherein the second graphics adapter is configured toprovide the image data to the first display device in the firstconfiguration and a scalable link interface between the first graphicsadapter and the second graphics adapter is disabled in the secondconfiguration.
 3. The system of claim 1, wherein the second graphicsadapter is configured to provide the image data to the second displaydevice in the first configuration and a scalable link interface betweenthe first graphics adapter and the second graphics adapter is enabled inthe second configuration allowing the second graphics adapter to provideimage data to the first display device though the first graphicsadapter.
 4. The system of claim 1, wherein the display driver is furtherconfigured to unload state information corresponding to the firstconfiguration from the first graphics adapter.
 5. The system of claim 1,wherein the display driver is further configured to load stateinformation corresponding to the second configuration into the firstgraphics adapter.
 6. The system of claim 1, wherein the first graphicsadapter is configured to provide image data to the second displaydevice.
 7. The system of claim 1, further comprising a control panelconfigured to receive a specification of the second configuration from auser.
 8. The system of claim 1, wherein the display driver is configuredto determine if there is a memory leak in the multiple graphics adapterprocessing system.
 9. A method of changing a configuration of a multiplegraphics adapter processing system, comprising: receiving aconfiguration specification for the multiple graphics adapter processingsystem; determining whether the configuration specification enables ordisables a scalable link interface between a first graphics adapter anda second graphics adapter in the multiple graphics adapter processingsystem; and changing from a first configuration of the first graphicsadapter and the second graphics adapter to a second configuration of thefirst graphics adapter and the second graphics adapter without shuttingdown the multiple graphics adapter processing system, wherein the secondconfiguration is defined by the configuration specification.
 10. Themethod of claim 9, wherein the configuration specification is providedby a control panel configured to receive user input.
 11. The method ofclaim 9, wherein the configuration specification is provided by thefirst graphics adapter or the second graphics adapter.
 12. The method ofclaim 9, further comprising determining if there is a memory leak in themultiple graphics adapter processing system.
 13. The method of claim 9,further comprising enabling the scalable link interface between thefirst graphics adapter and the second graphics adapter based on theconfiguration specification.
 14. The method of claim 9, furthercomprising disabling the scalable link interface between the firstgraphics adapter and the second graphics adapter based on theconfiguration specification.
 15. The method of claim 9, furthercomprising: shutting down an application program that is dependent onthe first graphics adapter before the changing from the firstconfiguration to the second configuration; and restarting theapplication program after the changing from the first configuration tothe second configuration.
 16. A computer readable medium storinginstructions for causing a processor to change a configuration of amultiple graphics adapter processing system by performing the steps of:determining whether a configuration specification enables or disables ascalable link interface between a first graphics adapter and a secondgraphics adapter in the multiple graphics adapter processing system; andchanging between a first configuration of the first graphics adapter andthe second graphics adapter and a second configuration of the firstgraphics adapter and the second graphics adapter without shutting downthe multiple graphics adapter processing system, wherein the secondconfiguration or the first configuration is defined by the configurationspecification.
 17. The computer readable medium of claim 16, wherein thefirst configuration specifies that the first graphics adapter providesimage data to a first display device and the second graphics adapterprovides image data to a second display device, and the secondconfiguration specifies that the first graphics adapter provides imagedata to the first display device and the second graphics adapterprovides image data to the first display device through the scalablelink interface.
 18. The computer readable medium of claim 17, whereinthe second configuration specifies that the first graphics adapterprovides image data to the second display device.
 19. The computerreadable medium of claim 16, further comprising determining if there isa memory leak in the multiple graphics adapter processing system. 20.The computer readable medium of claim 16, further comprising determiningif there an error condition exists in the multiple graphics adapterprocessing system.